Process for conditioning grape and analogous berry or fruit materials prior to extraction of juice therefrom



J 1958 s. K. WOLCOTT, JR 2,83

PROCESS FOR CONDITIONING GRAPE AND ANALOGOUS BERRY OR FRUIT MATERIALS PRIOR TO EXTRACTION OF JUICE THEREFROM Filed July 1, 1954 INVENTOR 3mm 11? 1/6100, J2

TORNEY S United States Patent C PROCESS FOR CONDITIONING GRAPE AND ANALOGOUS BERRY OR FRUIT MATERIALS PRIOR TO'EXTRACTION OF JUICE THERE- FROM Samuel K. Wolcott, Jr., Penn Yan, N. Y.

Application July -1, 1954, Serial No. 440,740

3 Claims. (Cl. 99-106) This invention relates to the art of commercial extraction of grape juice, as well as juices from other berries and fruits having similar juice constituency, such as blackberries.

The invention has for its general object the provision of a process for beneficiating the grape material prior to extraction with the end result of obtaining, irrespective of the methods of extraction or the apparatus employed, increased yield and improvement of the quality of the juice, greater facility and thoroughness in the separation of the solids, and speed-up in the process of extraction. The term extraction connotes any manner in which the juice is separated from the mass.

Another object of the invention is to provide a process for beneficiating the grape material prior to extraction,

through the concurrent and reciprocal effect of two additives, one a substance for degrading pectin, so as to release juice, and the other a finely divided substance hav ing fundamentally filter-aid properties, but having special characteristics conducive to the adhesion thereto of the solids particles resulting from the hydrolyzing of the pectin, as they are formed, as well as other solids, having a specific density somewhat greater than that of the juice so that it takes the attached solids out of suspension, and being preferably of fine filamentous nature, with microscopically rough or hairy surfaces, adapted to form a net-like web for holding and trapping the fines and other solids while at the same time letting the juice freely percolate through the web.

A further object of the invention is the provision of a continuous method of extraction, of which the beneficiating of the grape material in the manner set forth is an essential step.

Other objects of the invention will appear as the following description of the continuous method proceeds.

In the drawing which accompanies and forms a part of the following specification, the sole figure is a flow sheet disclosing diagrammatically the sequence of steps in the continuous method which has been employed herein for a description of the invention.

The subject process of beneficiating the grape material has, it is believed, made practicable for the first time a continuous process of extraction with its consequential saving in the cost of labor.

The older method consists in placing a quantity of crushed grapes in a press cloth, folding the cloth over the grapes, placing the cloth and contents between press racks, placing a number of such cloths with contents between racks in superposed relation and subjecting the stack to pressure of the order of 2500 pounds. An excessive amount of hand labor is required to load and unload the press box in this method; the juice production is relative low, and the juice in many instances being inferior on account of the unduly large content of solids. Various improvements upon the old procedure have been proposed, some affecting the method itself, and others representing advance in the apparatus employed, but none Patented June 3, 1958 of them have obviated the necessity of shutting down The essential novelty of the subject process resides in the incorporation of two additive agents to the grape material prior to extraction, and in their mutual and combinative functioning and effect in conditioning the grape material for extraction. These agents are:

(l) A pectin hydrolyzing enzyme, of Which'there are a number sold under proprietary names, and which essentially contain two types of pectin enzymes, pectin-polygalacturonase, commonly referred to as pectinase, and pectin-methylesterase, known briefly as pectase.

Their major reaction is hydrolysis of the pectic substances with resulting destabilization of the colloidal systems, reduction of high viscosity and formation of soluble and insoluble decomposition products.

(2) A fines intercepting and holding substance. in finely divided state providing an extended surface and having surface characteristics conducive to the attachment thereto and the retention thereby of the juice solids and particularly the colloidal debris resulting from the hydrolizing of the pectin, and having a specific density greater than that of the juice so that it takes the solids out of suspension and is discharged with the cake. An example of such substance is Wood pulp fiber which forms a net-like web to entrap the solids particles, and the individual fibers under the microscope show a surface roughened by the presence of hair-like processes adapted to catch and hold the solids. Such substances in general function also as filter aids, since in mass they are supported by mutual contact of their high spots, leaving channels between their noncontiguous surfaces.

It will be understood that the term solids throughout the specification and claims refers to skin, seeds and all cellular tissue or pulpy matter in various degrees of subdivision, not soluble in the juice, and that the term juice refers to the aqueous solution of sugar, acids, salt, pigments and flavor constituents, substantially free from insoluble matter. 7

Referring to a description of the exemplary method and to the flow sheet, the washed, stemmed and crushed grapes are heated to a temperature of 100 F. to 130 F. for supporting the reaction of the pectin hydrolizing enzyme. To the heated grape material contained in the tank 1, which is equipped with an agitator 2, is added from 0.1% to 0.2% enzyme, by weight. From 0.2% to 0.5% wood pulp, by weight, is also added, and the additives are well mixed with the grape mass so that the enzymes and fines intercepting medium are in mutual immediate proximity, and uniformly distributed throughout the grape material. The reaction of the enzyme reduces the viscosity of the mass, causes a disintegration, of the cellular structure, releases juice and forms pulpy debris. The enzyme also releases gases which if retained would render some of the insoluble particles buoyant so that under centrifugal action they would migrate into the juice zone of the centrifuge. As the particles are formed, they become immediately attached to the adjacent wood pulp filaments which are constituted as a net-like web distributed throughout the grape mass. These solids are thus immediately taken out of suspension and immobi-. lized in the fibrous web without being given the chanceto fiocculate and clog the channels permeating the fibrous web so as to impede the freedom of movement of the juice through the grape mass.

The above described treatment of the grape material is the essential process for the beneficiating or conditioning of the grape material to obtain optimum results in extraction regardless of the method or apparatusemployee.

After the enzyme has been permitted to react for thirty minutes toone hour, the grape material is heated from 140 F. to 160 F., depending upon the maturity of the grape for the purpose of extracting color. It is now pumped at a controlled rate into a continuous centrifugal extractor 3. The diagram represents an extractor of the type having a horizontal shell 4 rotatable at high speed and within which a screw blade 5 is mounted on a hollow rotatable shaft 6, the edges of which blade move close to the shell. The conditioned grape material is fed in at one end of the shaft and discharged at an intermediate zone of the centrifuge through ports 7. The wood pulp with the attached solids, and other solids, skin, seeds, pulp particles, etc., fly to the peripheryof the shell, the juice occupying an inner position with respect to the solids. The screw blade rotates in the same direction as the shell, but at a slightly lower speed, so that it pushes the solids continuously toward one end of the centrifuge and discharges them through an opening 8 at that end. The juice discharges through an opening 9 at the opposite end. Due to the fact that the grape mass comes to the centrifuge with the colloidal solids attached to the fibrous medium, and the specific gravity of thelatter is greater than that of the grape material,

the separation of solids and juice is unusually complete and clean cut, so that the juice issues with substantially no solids, having a clear and brilliant color.

The solids discharging from the centrifuge have about 65% moisture. They pass into a continuously operating vertical rotary press 10, comprising a shell 11, forming with the coaxial downwardly convergent spindle 12 an annular press chamber 13 of progressively diminishing capacity in a downward direction. The solids are admitted at the top and are progressively squeezed or compressed by means of fins 14 on the spindle. The juice discharges through various screens forming parts of the inner and outer wall of the press chamber. Due to the uniform distribution of the fibrous medium throughout the grape mass and the fact that the fines are immobilized on the fibrous material, the filter-aid function of the fibrous material is unusually efficient so that practically all the juice is extracted from the solids, and the cake is of unusually dry consistency. Since the juice from the press contains more solids than that from the centrifuge it is fed back to the centrifuge. The press cake discharges continuously against a gate-valve 15 at the bottom of the press chamber which yields against constant pressure.

Through the treatment of the grape material with I the hydrolizing enzyme, more juice is made extractable bothin the centrifuge and in the press than would be possible in the absence of such treatment, and because of the concurrent presence of the fibrous solids intercepting medium, in uniformly distributed pattern throughout the grape mass the enzyme action and the presence of the wood pulp reduces the slipperiness of the mass and increases internal friction, facilitating the action of the screw in a screw press for pressing and propelling the pulp through the press. The filter-aid function of said medium is also increased in direct ratio to the increase in extractable juice, while at the same time the solids are restrained from commingling with the juice as it is extracted.

In theabove described method it is obvious that if there is to be no interruption to the continuity of the extraction, a continuous supply of conditioned grape material must be available, so that the tank 1 shown in the flow sheet may be regarded as one of a battery of such tanks, successively connectable to the centrifuge.

The process of conditioning the grape material or the like as herein described makes it possible to process fruits such as grapes, blackberries, elde-rberries, etc., in various types of equipment that were previously inapplicable. For example, the following and other methods 7 of extraction are improved or made practicable by means of the treatment:

(1) Extraction by means of rack and bag, or rack and blanket press.

(2) Extraction by means of screw type press.

(3) Extraction by centrifugal force.

Previously, when a pectin hydrolizing agent was employed to. increase the amount of extractable juice, no attempt was made to control the behavior of the colloidal solids and fine pulp particles resulting from enzyme action. These remained suspended in the juice; were migratory and free to flocculate, that is, to mutually attach to one another and form appreciable masses. Due to their light specific density, they were difficultly separable from the juice in the centrifuge, and due to the tendency to fiocculate they clogged the drainage channels in the material in the press so that otherwise a a e juice o d no e adeq a e e p es d By the subject method of conditioning, the network lattice of colloid holding fibrous material pervades the entire mass of material, being present everywhere, in readiness to apprehend the decomposition colloids as soon as these are formed, and to hold them in situ where formed, so that in the centrifuge the colloids being attached to heavier fibers are readily separated from the juice, and in the press, the colloids being held in diffused position, cannot come together and fiocciulate, and therefore, cannot obstruct the drainage channels in the mass being compressed, including those channels provided between the fibers, acting as a filter-aid.

While I have in the above description disclosed a practical embodiment of the process of conditioning the grape material and of the continuous method of extraction made possible by the beneficiation of the material, it is to be understood by those skilled in the art that the process of beneficiation is to be considered Wholly independent of any specific type of apparatus for carrying it out, and that the continuous method as described and illustrated, is not tied to the apparatus disclosed.

What I claim is:

1. Process for conditioning grape material preparatory to the extraction of juice therefrom, comprising adding to a mass of grape material a pectin hydrolizing agent, and finely divided wood pulp fiber, the latter being characterized by a surface rough through the presence of hair-like processes enabling it to hold contacting solids particles freed in the mass as the result of disintegration of the fruit tissue, dispersing the additives throughout the mass by mixing, whereby the wood pulp fiber forms a three dimensional web-like network throughout the mass positioned to intercept, and inhibit the independent migration of, said particles, and maintaining the mixture at a temperature within the reaction range of the hydrolizing agent for a sufficient time to obtain a substantial hydrolizing effect, then progressively reducing the volume of the mass whereby the juice is extracted independently of the solids particles, the latter being retained in their relatively dispersed positions in said mass.

2. Process for conditioning grape material preparatory to the extraction of' juice therefrom, comprising adding to a mass of grape material from 0.1% to 0.2% by weight, of a pectin hydrolizing enzyme, and 0.2% to 0.5% of finely divided wood pulp fiber, the latter being characterized by a surface rough through the presence of hair-like processes enabling it to hold contacting solids particles freed in the mass as the result of disintegration of the fruit tissue, dispersing the additives throughout the mass by mixing, whereby the wood pulp fiber forms a three dimensional web-like network throughout the mass positioned to intercept, and inhibit the independent migra: tion of, said particles, and maintaining the mixture at a temperature within the reaction range of the hydrolizing agent for a sufficient time to obtain a substantial hydro-. lizing effect, .thenprogressively reducing the volume of the mass whereby the juice is extracted independently of the solids particles, the latter being retained in their relatively dispersed positions in said mass.

3. The method of extracting juice from fruit material containing native pectin, comprising conditioning the material preparatory to the juice extraction by adding thereto from 0.1% to 0.2% by weight of a pectin hydrolizing enzyme, and from 0.2% to 0.5% by weight of finely divided fibrous material having the rough surface characteristics of wood pulp fiber which enable it to hold contacting solids particles freed in the mass as the result of disintegration of the fruit tissue, agitating the mixture of said material and additives to secure uniform dispersion of the additives throughout the mass whereby the particles holding material forms a three dimensional web-like network throughout the mass positioned to intercept, and inhibit the independent migration of, said particles, hold- 6 ing the mass within a temperature range of from substantially 100 F. to 130 F. for a duration of substantially from thirty minutes to one hour, separating the optimum amount of substantially solids-free juice from the thus conditioned material, leaving a mass of solids with residual juice, and separating the extractable residual juice from said mass, then progressively reducing the volume of the mass whereby the juice is extracted independently of the solids particles, the latter being retained in their relatively dispersed positions in said mass.

References Cited in the file of this patent UNITED STATES PATENTS 1,991,242 Cole et al. Feb. 12, 1935 2,530,322 Ash Nov. 14, 1950 2,653,855 McColloch et a1 Aug. 14, 1951 Notice of Adverse Decision in Interference In Interference No. 90,490 involving Patent No. 2,837A31, S. K. Wolcott, Jr., Process for conditioning grape and analogous berry or fruit materials prior to extraction of juice therefrom, final judgment adverse to the patentee Was rendered Aug. 20, 1962, as to claims 1, Q and 3.

[Ofioz'al Gazette October 16, 1962.] 

1. PROCESS FOR CONDITIONING GRAPE MATERIAL PREPARATORY TO THE EXTRACTION OF JUICE THEREFROM, COMPRISING ADDING TO A MASS OF GRAPE MATERIAL A PECTIN HYDROLYZING AGENT, AND FINELY DIVIDED WOOD PULP FIBER, THE LATTER BEING CHARACTERIZED BY A SURFACE ROUGH THROUGH THE PRESENCE OF HAIR-LIKE PROCESSES ENABLING IT TO HOLD CONTACTING SOLIDS PARTICLES FREED IN THE MASS AS THE RESULT OF DISINTEGRATION OF THE FRUIT TISSUE, DISPERSING THE ADDITIVES THROUGHOUT THE MASS BY MIXING, WHEREBY THE WOOD PULP FIBER FORMS A THREE DIMENSIONAL WEB-LIKE NETWORK THROUGHOUT THE MASS POSITIONED TO INTERCEPT, AND INHIBIT THE INDEPENDENT MIGRATION OF, SAID PARTICLES, AND MAINTAINING THE MIXTURE AT A TEMPERATURE WITHIN THE REACTION RANGE OF THE HYDROLIZING AGENT FOR A SUFFICIENT TIME TO OBTAIN A SUBSTANTIAL HYDROLIZING EFFECT, THEN PROGRESSIVELY REDUCING THE VOLUME OF THE MASS WHEREBY THE JUICE IS EXTRACTED INDEPENDENTLY OF THE SOLIDS PARTICLES, THE LATTER BEING RETAINED IN THEIR RELATIVELY DISPERSED POSITIONS IN SAID MASS. 